Final answer:
Accounting is the essential component that Pacioli suggests is necessary for merchants to successfully run their business.
Step-by-step explanation:
Without accounting, Pacioli indicates that it is impossible for merchants "to conduct their business, for they would have no rest and their minds would always be troubled." Accounting provides the necessary tools and information for merchants to keep track of their financial transactions, calculate profits and losses, and make informed business decisions.
It helps them maintain accurate records, analyze their financial position, and ensure compliance with legal and regulatory requirements. Accounting practices are critical in ensuring that merchants can track their transactions, manage their finances systematically, and stay informed about the financial health of their enterprise, contributing to their peace of mind. Without robust financial management, it would indeed be hard for merchants to rest or have untroubled minds, as their business dealings would lack order and predictability, leading to potential chaos and uncertainty.